I land here:
While the URL indicates I should land about 3 screen heights lower.
If you go back using your browser button and then click the link again you land on the right location. This suggests some sort of caching or lazy loading might be the culprit. This happens most commonly in questions with multiple answers. It might be that the space reserved for images is on average too little, so that once the images are loaded the page has shifted within its frame.
This behaviour is both reported to occur in FireFox and Chrome latest stable versions.